Combustion heater



Oct. 3, 1950 2 Sheets-Sheet 1 Original Filed Dec. 21, 1942 y zirrneys.

Patented Oct. 3, 1950 COMBUSTION HEATER Theodore s. Briskin, SantaMonica, Calif., assignor to Excel Auto Radiator Company, Chicago, 111.,a corporation of Delaware Original application December 21, 1942, SerialNo. 469,668. Divided and this application May 11, 1948, Serial No.26,420

3 Claims. (01. 126 -91) This invention relates to improvements incombustion heaters of a type particularly adapted for use in automobilesor airplanes.

Combustion heaters of this type are generally provided with a sealedcombustion chamber in communication with the intake manifold of aninternal combustion engine. A mixture of gasoline and air is drawn intothe combustion chamber and is there ignited. The combustion chamher isgenerally provided with radiator fins and a blower to effect proper heatexchange. The outstanding characteristic of a'heater of this type isthat a great amount of heat can be generated in a very compact unit.This is accomplished in part by the use of a readily volatizable fuelsuch as gasoline so as to facilitate complete combustion, and in part bycausing the combustible mixture and products of combustion to flowthrough the heater at a rapid rate, thereby causing a greater rate ofcombustion than would normally occur in a heater of comparable size. Theterm combustion heater as hereinafter used refers specifically to aheater of the type having the above mentioned characteristics, ascompared with the usual type of fuel burning apparatus. a

The preferred embodiment of the invention herein shown and described isof a type adapted for use in automobiles or airplanes, but it isunderstood that this invention is not limited to use in connection witha vehicle operated with an internal combustion engine. A combustionheater embodying this invention is equally adaptable for use in otherapplications where the requisite pressure difference between the intakeand exhaust can be supplied.

The efliciency of a combustion heater is limited however by twoconsiderations: the type of heat exchange or heat dissipating meansprovided and the completeness of the combustion. The heat generated mustbe dissipated, not only to prevent overheating and damage to the heater,but to be useful, the heat must be dissipated by the heat exchange meansprovided in order that it may .not pass out through the exhaust in theform of high temperature products of combustion. On

the other hand, the temperature of the combustion zone must bemaintained sufficiently high as to insure complete combustion.

It has been the practice in the prior art to provide a chamber in whichthe combustion is caused to take place, the "walls of this chamberconstituting the heat exchange means. As the efiiciency of this heatexchange means is increased, as by the provision of radiator fins, ablower, and other structural improvements, the temperature of thecombustion chamber is lowered, thereby increasing the amount of carbonmonoxide in the flue gas and reducing the overall efficiency of theheater. As a practical matter, it

is difficult to achieve the correct balance between heat exchangecapacity and the proper temperature of the combustion chamber, with theresult that complete combustion is attained only in' combination withinsuflicient heat ex change capacity or inefficient heat exchange means.A large portion. of the heat is thereby Wasted. In'other words, wherethe wall of the combustion chamber forms a part of the heat exchangemeans, the result is inefficient operation, the flue gas either being ofexcessive temperature, or else containing an unduly large proportion ofcarbon monoxide.

In the present invention, the wall of the combustion chamber does notconstitute a portion of the heat exchange means. A manifold chamber isprovided for the products of combustion, and

the combustion chamber is disposed within the manifold chamber, andspaced from the walls thereof so that the combustion chamber issurrounded by the hot products of combustion. The

temperature difference on either side of the wall of the combustionchamber being comparatively small, a high temperature may be maintainedwithin the combustion chamber which will result in substantiallycomplete combustion of the fuel and its dissociation products.

It is a further object of this invention to providean improvedarrangement of parts within the manifold chamber, such as thearrangement of the baifles, and the arrangement of the combustionchamber, and an outlet conduit, so that the products of combustion arecaused to circulate along the entire periphery of the side walls of themanifold chamber before .being finally educed, thus effecting a maximumheat exchange. In this connection it will be further noted that thedesign of the manifold chamber herein disclosed is such that it can bedie cast in integral form, with the exception of one side wall. Theremaining parts are so designed that they are independently mounted withrespect to the die casting, thus providing a minimum of joints throughwhich gas may escape.

Various other objects, features and advantages will become apparent asthe description proceeds. Reference is hereby made to the accompanyingdrawings which form a part of this specification, and in which apreferred embodiment of this invention is illustrated, like referencenumerals referring to like parts:

Fig. l is a plan section of a preferred embodiment of this invention;

Fig. 2 is an end View of the heater shown in Fig. l, the gasoline mixingchamber being shown in section; and

Fig. 3 is a section taken along line 33 of Fig. 1.

With reference now to Figs. 1 and 2, the heater c mpri e a housing l0surrounding the I four sides of the heater. A motor |2 is positionedabove the housing I9 and is mounted by means of motor brackets |3 which,as shown in Fig. 2, may be secured to the housing by any suitable means,such as by a screw and a spacer. A fan, not shown, is driven by themotor, the fan being positioned in the upper portion of the housing Iand above a plurality of fins l5 which are enclosed by the housing.

A manifold chamber |6 is disposed within the housing, the fins beingmounted on the manifold chamber and being held in spaced relation witheach other by any suitable means, such as by welding the fins to thewalls of the manifold chamber. The manifold chamber is provided with aflange ll into which a plurality of studs 3 are threaded whereby themanifold chamber may be secured.

A plate l9 having two cylindrical bosses 20 and 2| cast integrallytherewith is positioned adjacent the housing H] at a point opposite themanifold chamber l6. A heat resistant gasket 22 is interposed betweenthe plate l9 and the side wall of the housing, and a similar heatresistant gasket 23 is positioned between the manifold chamber and theside wall of the housing, the studs l8 passing through the plate l9, thegaskets 22 and 23, and the side wall of the housing l0, so that thewhole assembly may be rigidly secured together.

The boss 29 is drilled to receive an inlet tube 24 which extends into alarger cavity formed within the boss which cavity may be referred to asthe ignition chamber 25. A heat resistant cup-shaped member 26, theclosed end of which is perforated so as to provide a bafiie 21, isfitted into the ignition chamber. Discs 23 and 29 of refractory materialare positioned adjacent the open end of the cup-shaped member 26, thedisc 28 being perforated at its central portion and being undercutperipherally thereof to form an annular chamber as indicated at 3|], andthe disc 29 being provided with a plurality of peripherally arrangedperforations 3| to form passageways communicating with the chamber 39.The bore in the boss 26 is threaded as indicated at 32, and a closedtube 33 is threaded into the boss and confines the cup-shaped member 26and the discs 28 and 29 in position. The closed tube 33 forms acombustion chamber 35, the remote end of the tube being provided with aslot 34 through which burning gases may escape from the combustionchamber.

- The boss 2| is drilled to provide an outlet passage 36, a portion ofthe boss being internally threaded as indicated at 31, and a closed tube38 being screwed into the boss so as to form a continuation of theoutlet passageway 36. A slot 39 is formed in the closed tube 38, theslot running substantially the full length of the tube.

The manifold chamber I6 is preferably die cast in a single piece havingan end wall 49 and walls Al, 42, 44, and 46 which can be referred togenerically as side walls. The interior of the manifold chamber isdivided into three communicating compartments by a bafile 43 whichextends downwardly from the upper side wall 44 and a baflle 45 whichextends upwardly from the lower side wall 46. The upper and lower wallsare curved as shown in Fig. 3.

When the manifold chamber l6 and the assembly, comprising plate l9 andits associated parts described above, are secured together by means ofthe studs l8, it will be noted that the closed tube 33 is received inone of the comp r ments of the manifold chamber and the outlet tube 38is received in another compartment, as shown in Fig. 3. The flow of gasfrom the tube 33 to the outlet tube 38, as shown by arrows in Figs. 1and 3, is caused to follow the side walls of the manifold chamber |6 dueto the arrangement of the baflies 43 and 45. This permits a maximumamount of heat exchange with the walls of the manifold chamber and themanifolding causes the maximum heat available to be extracted from theproducts of combustion before they are finally educed from the manifoldchamher. It will be noted that the tubes 33 and 38 are independently andrigidly mounted with respect to the manifold chamber I6, with theirclosed ends abutting against the end wall 40 of the manifold chamber.

A tubular member 50 is disposed above the inlet boss 25, as shown inFig. 2, and is provided with two arms 5| and 53. The arm 5| is drilledto provide a mixing chamber 52 at the lower portion thereof, and the arm53 terminates in a clamp 54 which is secured to the outlet boss 2|, asshown in Fig. 2. By means of this clamp, the tubular member 59 and itsassociated parts are mounted with respect to the other portions of theheater.

The mixing chamber 52 is provided with a liner 55 which is in the formof a Venturi tube. The upper portion of the arm 5| is drilled to providea gasoline passageway 51, and a gasoline supply tube 56 is positioned inthe passageway and extends downwardly to the constricted portion of theVenturi tube. A plurality of laterally disposed air inlets 58 are formedin the arm 5| at the upper portion of the mixing chamber. It will beseen that the parts just described function in the usual manner tocarburet the gasoline which is fed into the ignition chamber 25.

A gasoline supply line may be suitably connected to gasoline passageway51, through a suitable control valve. A plug 62 closes the lower end ofthe mixing chamber and holds the liner 55 in place. A passageway 66provides communication between the mixing chamber 52 and the inlet tube24. The lower portion of the arm 5| is secured to the end surface of theboss 20 by means of screws 64, and a heat resistant gasket 63 isinterposed between the two members.

A spark plug 65 is mounted in the wall of the ignition chamber 25 sothat the carburetted gasoline which is drawn into the ignition chambermay be ignited. The burning mixture then passes through the passagewaysin the discs 28 and 29 and further combustion takes place in thecombustion chamber 35. The hot gases then pass through the outletpassageway 36 and through a conduit 61 into the intake manifold of thegasoline engine. The conduit 61 is screw-threaded into the end of theboss 2|, as shown in Fig. 1. After combustion continues for a shortperiod of time, the refractory discs 28 and 29 become heated to thestate of incandescence so that the ignition provided by the spark plug65 is no longer needed. Suitable means may be provided for breaking thecircuit to the spark plug when this state has been attained. It will benoted in this connection that the combustible mixture in passing fromthe ignition chamber 25 into the combustion chamber 35 is exposed toheat radiated from all directions due to the undercut construc tion ofthe discs 28 and 29, and all the heat so radiated is absorbed by thecombustible mixture. Furthermore, any unvaporized droplets of gasoline,having a greater inertia than the vapor, will impinge upon the centralportion of the disc 29 perforations 3| into the combustion chamber Theconstruction herein illustrated has been found to form a highlyefficient means of ignition. In operation, when the heater is initiallyturned on, ignition is effected by the spark plug 65. Thus, apartialcombustion of the mixture will occur in the ignition chamber 25 whichheats the refractory discs 28 and 29. After the discs have been heatedto an incandescent state, the spark plug circuit is automaticallyopened, and the mixture thereafter is ignited as it passes through therefractory discs 28 and 29.

The provision of the tube 33 separates the zones of combustion and heatexchange, with the result that the wall of the combustion chamber 35 ismaintained at a high temperature which promotes complete combustion ofthe fuel. The arrangement of the manifold chamber 16, as

. pointed out above, is such that the products of combustion are causedto follow. the side walls of the manifold chamber throughout itscomplete periphery, and the flow stream of these products spreads outfanwise as it approaches the slot 39 in the outlet tube 38. Thus themaximum amount of heat exchange through the side walls of the combustionchamber is permitted to take place.

This application is a division of my copending application, Serial No.469,668, filed December 21, 1942, now Patent No. 2,457,862, grantedJanuary 4, 1949, and the subject matter thereof, insofar as it isconsistent with this application, is hereby incorporated by referenceinto this application.

Although only a preferred modification of this invention has been shownand described herein, it will be understood that various modificationsand changes may be made therein without departing from the spirit ofthis invention. It is understood that the foregoing is intended to beillustrative only, and that this invention is to be limited only by thefollowing claims.

I claim:

1. A heater of the combustion type comprising a plate having a tuberigidly mounted on said plate and extending from one side thereof, meanssecured to said plate in gas tightrelationship and providing a chamber,said tube extending into said chamber and being completely surroundedthereby and being provided with means forming an outlet in the side wallof said tube for communication with said chamber, and being spaced fromthe side walls of said chamber, means forming an outlet for saidchamber, refractory means disposed at the inlet of said tube to ignite agaseous fuel as it flows into said tube so as to cause the combustionthereof as it passes longitudinally through said tube, andlongitudinally arranged bafiie means disposed between said tube and saidchamber outlet forming means and extending inwardly from a side wall ofsaid chamber to cause the products of said combustion to circulateoutwardly from and in a peripheral direction, with respect to said tube,in the space between said tube and the side walls of said chamber beforepassing out of said chamber to said outlet, and heat exchange meansoperatively associated with the external surface of the side Walls ofsaid chamber.

2. In a heater of the combustion type, means forming an elongatemanifold chamber having an end wall and side walls, a plurality ofbafiies longitudinally disposed within-said chamber dividing the sameinto a plurality of communicating compartments including a'firstcompartment, a last compartmentand an intermediate compartment, tubularmeans forming a combustion chamber mounted on said end wall andextending into said first compartment, means forming an outlet in theside wall of said tubular means for communication with said firstcompartment, and means forming an outlet for said last compartment, eachof said bafiles extending from one side Wall of said manifold chambertoward an op posite side wall, but terminating short of the latinto saidfirst compartment and through said other communicating compartments andinto said outlet, said combustion chamber being spaced from the sidewalls of said manifold cham ber, whereby matter surrounding saidmanifold chamber is heated by heat exchange with said products ofcombustion through the side walls of said manifold chamber and thetemperature within said combustion chamber is maintained at asufficiently high degree as to insure substantially complete combustionwithin said combustion chamber.

3. In a heater of the combustion type, means forming an elongatemanifold chamber having an end wall and side walls, a plurality ofbaffles longitudinally disposed within said chamber dividing the sameinto a plurality of longitudinally disposed communicating compartmentsincluding a first compartment, a last compartment, and an intermediatecompartment, tubular means forming a combustion chamber mounted on saidend wall and extending'into said first compartment, means forming anoutlet in the side wall of said tubular means for communication withsaid first compartment, an outlet conduit mounted on said end wall andextending into said last compartment, each of said baflles extendingfrom one side Wall toward an opposite sidewall and terminating short ofthe latter to provide communicating means between adjacent compartments,adjacent baflies extending from opposite walls so that as the productsof combustion pass from said first-mentioned compartment through saidother communicating compartments and into said outlet conduit the flowstream of said products of combustion will contact the side walls ofsaid manifold chamber along the entire periphery thereof, and a.longitudinal, slot in the wall of said outlet conduit of a lengthapproximating the length of the compartment in which said conduit isdisposed to cause said flow stream to broaden out. so as to increase thearea of contact between said flow stream and said side Walls,

thereby increasingthe heat exchange throughv said side walls.

THEODORE S. BRISKDN'. REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATESQPATENTSK t Date

